Slitting machines for cutting sheet material such as plastic, paper or fabric are well known in the art. Typically, a slitting machine employs an arbor having a plurality of circular cutting discs laterally spaced thereon. The edge of the cutting discs rotate against an anvil which is mounted on a arbor adjacent to the cutting discs. As sheet material is feed between the cutting discs and anvils, it is cut strips of material.
One of the problems associated with slitting machines is that proper operation depends on maintaining engagement of the cutting knives with the anvils. The engagement of the cutting knives with the respective anvils can be affected by many factors including variations in the diameter of the cutting knives or anvils, eccentricity of the cutting knives or anvils, flexing of the arbors, and wear of the cutting knives and anvils.
In order to compensate for the above mentioned problems, attempts have been made to resiliently mount the anvils. One approach has been to employ a core around which a plurality of anvil rings are resiliently mounted. This approach is illustrated in U.S. Pat. No. 3,677,122. The above mentioned patent discloses a slitting machine having first and second arbors. A cutting disk is mounted to the first arbor. The anvil assembly comprises a first annular ring mounted to the second arbor. A second annular ring is concentrically disposed about the first annular ring. An elastomer means is disposed between the first and second annular rings for resiliently holding the annular rings into pre-loaded engagement with at least one cutting disc on the first arbor.
While the device described in the '122 patent has a number of drawbacks. First, since the elastomer means is disposed between the first and second and the annular rings, it limits radial displacement of the outermost annular ring. Further, because the elastomer means is bonded to both the core and the annular rings, relative movement between the first and second annular is not possible. Another drawback of the anvil described in the '122 patent is that no means is provided for varying the resistance of on the annular rings to radial displacement. Finally, since the elastomer means generally has a relatively low melting point, the anvil means of the '122 patent has limited utility in applications where heating is required.